Book Image

Linux Service Management Made Easy with systemd

4.5 (2)
Book Image

Linux Service Management Made Easy with systemd

4.5 (2)

Overview of this book

Linux Service Management Made Easy with systemd will provide you with an in-depth understanding of systemd, so that you can set up your servers securely and efficiently.This is a comprehensive guide for Linux administrators that will help you get the best of systemd, starting with an explanation of the fundamentals of systemd management.You’ll also learn how to edit and create your own systemd units, which will be particularly helpful if you need to create custom services or timers and add features or security to an existing service. Next, you'll find out how to analyze and fix boot-up challenges and set system parameters. An overview of cgroups that'll help you control system resource usage for both processes and users will also be covered, alongside a practical demonstration on how cgroups are structured, spotting the differences between cgroups Version 1 and 2, and how to set resource limits on both. Finally, you'll learn about the systemd way of performing time-keeping, networking, logging, and login management. You'll discover how to configure servers accurately and gather system information to analyze system security and performance. By the end of this Linux book, you’ll be able to efficiently manage all aspects of a server running the systemd init system.
Table of Contents (23 chapters)
1
Section 1: Using systemd
12
Section 2: Understanding cgroups
16
Section 3: Logging, Timekeeping, Networking, and Booting

Using journalctl

The journalctl utility is cool because it has so much flexibility. Let's start by looking at the various ways to search for and display log data. We'll do this on the Ubuntu machine because Ubuntu's persistent journald logs will give us more to look at.

Searching for and viewing log data with journalctl

The simplest command for viewing log files is just journalctl. As we see here, this will show you pretty much the same information that you'd see when you open a normal rsyslog file in less. You'll also see that the journalctl output is automatically piped into less:

donnie@ubuntu2004:~$ journalctl
-- Logs begin at Tue 2021-01-05 20:46:55 EST, end at Tue 2021-08-10 14:23:17 ED>
Jan 05 20:46:55 ubuntu2004 kernel: Linux version 5.4.0-59-generic (buildd@lcy01>
Jan 05 20:46:55 ubuntu2004 kernel: Command line: BOOT_IMAGE=/vmlinuz-5.4.0-59-g>
Jan 05 20:46:55 ubuntu2004 kernel: KERNEL supported cpus:
Jan 05 20:46:55 ubuntu2004 kernel...